Image-displaying device and image data generation device

ABSTRACT

An image-displaying device includes an image data generation section, a progress information acquisition section and a display control section. The image data generation section is configured to perform processing for generating image data indicative of an image of a subject based on output data from an image-capturing section that captures the image of the subject, the image data being composed of a plurality of predetermined data units. The progress information acquisition section is configured to acquire progress information indicative of a status of progress of the processing for generating the image data with respect to each of the predetermined data units of the image data. The display control section is configured to control the display section to display at least one of the predetermined data units of the image data for which the processing for generating the image data is ended based on the progress information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 13/109,436 filed on May 17, 2011. This applicationclaims priority to Japanese Patent Application No. 2010-113978 filed onMay 18, 2010 and Japanese Patent Application No. 2010-214841 filed onSep. 27, 2010. The entire disclosures of U.S. patent application Ser.No. 13/109,436 and Japanese Patent Application Nos. 2010-113978 and2010-214841 are hereby incorporated herein by reference.

BACKGROUND

Technical Field

The present invention relates to an image-displaying device fordisplaying an image of a subject in a display section, and to a displaytiming control circuit.

Related Art

Conventional image-capturing devices are known in which an imagecaptured by an image-capturing sensor is displayed by a liquid crystaldisplay, and various techniques have been developed for preventing adelayed display of the image of the subject from occurring in the liquidcrystal display. In Japanese Laid-Open Patent Application PublicationNo. 2007-243615, for example, a technique is disclosed whereby an imagesignal is read and displayed by a liquid crystal display before writingof the image signal of a single frame to the VRAM is completed in animage-capturing device provided with a VRAM for recording an imagesignal of a single frame. Specifically, a configuration is described inwhich image display by a liquid crystal display is started at a playbacktiming that is delayed by ΔT from the drive timing of theimage-capturing sensor.

SUMMARY

In the technique of Japanese Laid-Open Patent Application PublicationNo. 2007-243615, the cycle of the drive timing and the playback timingis the cycle for processing an image of a single frame, and a constantΔT is defined for each frame. In other words, in the technique of thispublication, ΔT is described as being defined for each mode (JapaneseLaid-Open Patent Application Publication No. 2007-243615, paragraph[0057]), and ΔT is determined so that reading of image data does nottake place before writing thereof (Japanese Laid-Open Patent ApplicationPublication No. 2007-243615, paragraphs [0055] and [0056]).Consequently, although ΔT may fluctuate for each mode, ΔT is a commonvalue for each frame in the same mode, and the same phase difference ΔTis given for all lines of the image that is to be displayed.

However, in a configuration in which image processing for displaying theimage of a subject in a display section is performed based on outputdata of an image-capturing sensor, the period needed for each type ofimage processing may be different for each line. Therefore, in order toprovide a common phase difference ΔT and thereby prevent the reading ofimage data from taking place before writing thereof in all the lines ofthe image that is to be displayed, ΔT must be defined so as to have amargin so that reading does not occur prematurely. For example, indefining ΔT, it is necessary to make such considerations as assumingthat the maximum period is needed for various types of image processingfor all the lines. Consequently, in a configuration in which the periodneeded for image processing may fluctuate in line units, a delay mayoccur in line units in the period between capturing of the subject bythe image sensor and displaying in the display section.

The present invention was developed in view of the foregoing problems,and an object of the present invention is to satisfactorily display asubject in a display section.

In order to achieve the objects described above, a configuration isadopted in which progress information indicating the progress ofprocessing for generating image data for individual predetermined dataunits is acquired, and the predetermined data unit for which theprocessing for generating image data is ended is displayed in a displaysection based on the progress information. In other words, predetermineddata units for which processing for generating image data is ended aredisplayed in sequence in the display section. Consequently, it ispossible to minimize the time lag between display of a certainpredetermined data unit and display of the next predetermined data unit,and to shorten the display delay of the subject in the display section.

The predetermined data unit herein may be a single line, a plurality oflines, or another unit. The image data generation section is alsopreferably capable of generating image data indicating an image of asubject based on output data of an image-capturing section (e.g., anarea image sensor), and displaying the image of the subject in thedisplay section based on the image data. The processing for generatingimage data may be composed of any type of image processing, and theperiod required for processing may fluctuate according to the outputdata of the image-capturing sensor, a mode in the image-displayingdevice, the image-capturing conditions, or other factors. The periodrequired for processing may also be unknown. In other words, since theprogress of the processing for generating image data is dynamicallyspecified by the progress information acquisition section, regardless ofthe type of processing performed, there is no need for the requiredperiod thereof to be specified in advance prior to the start of theprocessing.

The progress information acquisition section is preferably capable ofacquiring progress information which indicates the progress of theprocessing for generating image data for individual predetermined dataunits. In other words, since a predetermined data unit for whichprocessing for generating image data is ended can be displayed by thedisplay section, the progress information is preferably defined asinformation whereby it is possible to determine for individualpredetermined data units whether the processing for generating imagedata thereof is ended. Consequently, the progress information may beinformation directly or indirectly indicating that processing forgenerating image data is ended for any predetermined data unit.

In the former case (direct information), the information may be composedof information indicating that the processing for generating image dataof a single predetermined data unit is ended, information indicatingthat the processing for generating image data which indicate a pixelwhich is positioned at the end of a single predetermined data unit andis last to be processed is ended, information indicating a predetermineddata unit number of a predetermined data unit targeted for theprocessing for generating image data, or other information, for example.In the latter case (indirect information), in a case in which theprocessing for generating image data is composed of a plurality of imageprocessing steps, and the steps include a step in which the requiredperiod needed for an image processing step dynamically fluctuates, and astep in which the required period is constant, the information may becomposed of information indicating that all steps are ended in which theperiod needed for an image processing step dynamically fluctuates. Inother words, since the required period is constant for steps other thansteps in which the period needed for an image processing step maydynamically fluctuate, insofar as it can be specified for a certainpredetermined data unit whether a step is ended in which the periodneeded for an image processing step may dynamically fluctuate, it ispossible to specify the timing at which the processing for generatingimage data ends for the certain predetermined data unit.

The display control section is preferably capable of causing the displaysection to display a predetermined data unit for which the progressinformation specifies that processing for generating image data isended. In other words, the display control section is preferablyconfigured so as to stand by without displaying a predetermined dataunit when the processing for generating the image data indicating thepredetermined data unit is not ended in image data indicating an imagein which a single frame is composed of a plurality of predetermined dataunits, and to start display of the predetermined data unit in responseto ending of the processing for generating the image data.

A configuration in which a plurality of image processing steps isexecuted by image data generation processing may be assumed as apreferred configuration of the image-displaying device. In this case, byadopting a configuration in which information indicating a predetermineddata unit for which the final step of a plurality of image processingsteps is ended is acquired as the progress information, it is extremelyeasy to specify based on the progress information that the processingfor generating image data is ended. Therefore, by displaying thepredetermined data unit for which the final step of the plurality ofimage processing steps is ended in the display section, display in thedisplay section can be performed while shortening the display delay ofthe subject.

In a configuration in which image data are generated which can bedisplayed in the display section via a plurality of image processingsteps based on the output data of the image-capturing sensor, the starttiming of execution of each step may be controlled in accordance withthe progress of each step for individual predetermined data units. Inother words, a relationship is assumed in which processing forgenerating data of a Z^(th) predetermined data unit by an (X+1)^(th)image processing step among the plurality of image processing stepscannot be started unless data of a Y^(th) predetermined data unit isgenerated by an X^(th) image processing step among the plurality ofimage processing steps. In this case, a configuration is assumed inwhich processing for generating data of the Z^(th) predetermined dataunit in the (X+1)^(th) image processing step is started in a case inwhich a determination is made based on the progress information that thedata of the Y^(th) predetermined data unit is generated by the X^(th)image processing step. Through this configuration, the wait time duringexecution of each image processing step is minimized, and it is possibleto minimize the time lag between capture of the subject image by theimage-capturing sensor and display thereof by the display section. Inthis arrangement, X may be any or all natural numbers equal to or lessthan the number of image processing steps minus one, and Y is anynatural number equal to or less than the maximum value of thepredetermined data unit number generated by the X^(th) image processingstep. The value Z is any natural number equal to or less than themaximum value of the predetermined data unit number generated by the(X+1)^(th) image processing step.

Various configurations may be adopted for controlling the predetermineddata unit displayed in the display section. For example, the presentinvention may be applied to a display section for displaying individualpredetermined data units within the output interval of a horizontalsynchronization signal. For example, a configuration may be adopted inwhich a horizontal synchronization signal is outputted in a case inwhich progress information indicates that processing for generatingimage data of a single predetermined data unit is ended, and display isperformed in the display section based on the image data of the singlepredetermined data unit for which the generation processing is endedwhen the horizontal synchronization signal is outputted. In other words,the horizontal synchronization period prescribed by the horizontalsynchronization signal is of variable length. Through thisconfiguration, the period spent to display individual predetermined dataunits can easily be adjusted, and display can easily be performed forindividual predetermined data units in accordance with the adjustedperiod.

It is also possible to apply as a program or a method the technique ofthe present invention whereby a determination is made for individualpredetermined data units as to whether the processing for generatingimage data is ended based on the progress information, and thepredetermined data unit for which the generation processing is ended isdisplayed. A circuit, device, program, or method such as described abovemay be implemented as an independent circuit or device, as well as byutilizing a shared component in a circuit or device having multiplefunctions, and various forms of implementation are included.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of thisoriginal disclosure:

FIG. 1 is a block diagram according to an embodiment of the presentinvention;

FIG. 2 is a diagrammatic view showing the number of pixels of the areaimage sensor and the liquid crystal panel;

FIG. 3 is a view showing an example of the method for outputting theoutput data of the area image sensor;

FIG. 4 is a timing chart showing the signals applied to the displaysection according to the present embodiment;

FIG. 5 is a timing chart according to another embodiment of the presentinvention; and

FIG. 6 is a block diagram according to another embodiment of the presentinvention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments of the present invention will be described in the followingorder: (1) Configuration of the image-capturing device; (2) Control ofthe horizontal synchronization signal; and (3) Other embodiments.

(1) Configuration of Image-Capturing Device

The image-capturing device 1 (image-displaying device) according to anembodiment of the present invention shown in FIG. 1 is provided with anoptical system 10, an area image sensor 15 (corresponding to theimage-capturing section), an ASIC 200, a timing generator 30, a displaysection 40, a CPU 50, a VRAM 51, an SD-RAM 52, a ROM 53, a RAM 54, andan operating section 55. The CPU 50 is capable of executing a programrecorded in the ROM 53 by appropriately utilizing the VRAM 51, theSD-RAM 52, and the RAM 54, and through this program, the CPU 50 executesa function for generating image data which indicate a subject capturedby the area image sensor 15, in accordance with an operation of theoperating section 55. The operating section 55 is provided with ashutter button, a dial switch as a mode switching means for switching amode, a dial switch for switching an aperture and a shutter speed, and apush button for operating various types of setting menus, and a user canissue various types of instructions to the image-capturing device 1 byoperating the operating section 55.

The display section 40 is an EVF (electronic view finder) for displayingan image indicating a subject to be captured and allowing the user tocomprehend the appearance of the subject prior to the capturing of theimage, and image-capturing conditions and other information, and theimage-capturing device 1 according to the present embodiment is amirrorless digital camera provided with an EVF. The display section 40is provided with an interface circuit not shown in the drawing, a liquidcrystal panel driver 41, a liquid crystal panel 42, and an eyepiece lensand other components not shown in the drawing. In the presentembodiment, the liquid crystal panel 42 is a high-temperaturepolysilicon TFT (Thin Film Transistor) provided with three sub-pixelscorresponding to three colors of color filters for each pixel, and thepositions of the pixels are prescribed by coordinates in an orthogonalcoordinate system. A line is composed of a plurality of pixels alignedin the direction parallel to one coordinate axis, and a plurality oflines is aligned in the direction parallel to the other coordinate axis.In the present specification, the direction parallel to the lines isreferred to as the horizontal direction, the direction perpendicular tothe lines is referred to as the vertical direction, and a single screencomposed of all the pixels of the liquid crystal panel 42 is referred toas a single frame.

The liquid crystal panel driver 41 applies a voltage to each sub-pixeland outputs a signal for driving the liquid crystals to the liquidcrystal panel 42. The liquid crystal panel 42 is provided with a gatedriver and a source driver not shown in the drawing, and performsdisplay by a process whereby the gate driver controls the display timingin each pixel of each line in accordance with the signal outputted fromthe liquid crystal panel driver 41, and the source driver applies avoltage that corresponds to the image data of each pixel to each pixelof a line designated by the display timing. In other words, the liquidcrystal panel driver 41 is configured so as to output various types ofsignals for performing display in the liquid crystal panel 42, e.g., avertical synchronization signal (DVsync) for prescribing a period fordisplay of a single frame; a horizontal synchronization signal (DHsync)for prescribing a period for display of a single line; a data activesignal (DDactive) for prescribing a period for importing image datawithin each line; a data clock signal (DDotclock) for prescribing theimport timing of image data of each pixel; and image data (Data) of eachpixel.

The image-capturing device 1 according to the present embodiment isprovided with the timing generator 30, and the vertical synchronizationsignal DVsync, the horizontal synchronization signal DHsync, the dataactive signal DDactive, and the data clock signal DDotclock aregenerated by the timing generator 30. In other words, the timinggenerator 30 is provided with a display control section 30 b which isprovided with a division circuit or the like for generating a signal inwhich the signal level varies in synchrony with the variation timing ofa clock signal having a predetermined cycle outputted from a clocksignal generation means. By control of the display control section 30 b,the timing generator 30 generates the vertical synchronization signalDVsync, data active signal DDactive, and data clock signal DDotclock inwhich the signal levels vary at a timing determined in advance. Theoutput timing of the horizontal synchronization signal DHsync isvariable in the present embodiment, and the output timing is determineddepending on the processing result of a resizing processing section 20e, as described hereinafter.

The liquid crystal panel 42 in the present embodiment is a panel havingan XGA-size pixel count provided with 1024 effective pixels in thehorizontal direction and 768 effective pixels in the vertical direction,and can display gradations corresponding to the Data in any position byadjusting the content and output timing of the image data Data outputtedby the liquid crystal panel driver 41. In the present embodiment, aconfiguration is adopted in which an image of the subject is displayedbased on the output data of the area image sensor 15 in a subject imagedisplay region of the liquid crystal panel 42 determined in advance, andcharacters indicating image-capturing conditions or other informationare displayed in an information display region outside the subject imagedisplay region. In other words, characters indicating image-capturingconditions or other information are displayed as an OSD (on-screendisplay) together with the image of the subject in the liquid crystalpanel 42. The liquid crystal panel 42 is provided with a large number ofpixels in excess of the effective pixels in the horizontal direction andthe vertical direction, but in order to simplify the presentspecification, no description is given of the processing that relates topixels other than the effective pixels.

The optical system 10 is provided with a lens 11 for forming a subjectimage on the area image sensor 15, and an aperture 12, a shutter 13, anda low-pass filter 14. Among these components, the lens 11 and theaperture 12 are replaceably attached to a chassis not shown in thedrawing. A CMOS (complementary metal oxide semiconductor) image sensor,CCD (charge coupled device) image sensor, or other solid image-capturingelement provided with color filters arranged in a Bayer array, and aplurality of photodiodes for accumulating a charge according to aquantity of light by photoelectric conversion for each pixel is used asthe area image sensor 15. The positions of the pixels of the area imagesensor 15 are prescribed by coordinates in an orthogonal coordinatesystem, wherein a line is composed of a plurality of pixels aligned inthe direction parallel to one coordinate axis, and a plurality of linesis aligned in the direction parallel to the other coordinate axis. Inthe present specification, the direction parallel to the lines isreferred to as the horizontal direction, the direction perpendicular tothe lines is referred to as the vertical direction. A single screencomposed of all the pixels of the area image sensor 15 is referred to asa single frame.

In the present embodiment, the area image sensor 15 also operates insynchrony with the various types of signals outputted by the timinggenerator 30. In other words, the timing generator 30 outputs a verticalsynchronization signal (SVsync) for prescribing a period for reading thedetection results of the photodiodes for a single frame; a horizontalsynchronization signal (SHsync) for prescribing a period for reading thedetection results of the photodiodes for a single line; and a data clocksignal (SDotclock) for prescribing the read timing and the like of imagedata of each pixel. The area image sensor 15 starts outputting theoutput data for a single frame in accordance with the verticalsynchronization signal SVsync, and sequentially reads output data whichindicate the detection results of the photodiodes corresponding to aportion of the pixels of the area image sensor 15 at a timing inaccordance with the data clock signal SDotclock within the periodprescribed by the horizontal synchronization signal SHsync.

The ASIC 200 is provided with an image data generation section 20 whichis composed of a circuit for performing processing whereby line buffers52 a through 52 d for a plurality of lines reserved in advance in theSD-RAM 52 are utilized, and image data for displaying an image of thesubject in the display section 40 are generated by pipeline processing.The line buffers 52 a through 52 d for a plurality of lines may also beprovided to the image data generation section 20 or another component.The display section 40 displays the subject on the liquid crystal panel42 based on the generated image data. In other words, the user canconfirm the subject while utilizing the display section 40 as an EVF.The ASIC 200 may also be an image processing DSP (digital signalprocessor).

In a case in which the user operates the operating section 55 to issuean image capture instruction, in response to the image captureinstruction, the area image sensor 15 starts outputting the output datafor a single frame in accordance with the vertical synchronizationsignal SVsync, and sequentially reads the output data which indicate thedetection results of the photodiodes corresponding to all of theeffective pixels of the area image sensor 15 at a timing in accordancewith the data clock signal SDotclock within the period prescribed by thehorizontal synchronization signal SHsync. The image data generationsection 20 then utilizes the SD-RAM 52 or another component to generateimage data in a JPEG format or other format, and the image data arerecorded in a removable memory or the like not shown in the drawing. Inother words, the user can generate image data for indicating thesubject.

(2) Control of Horizontal Synchronization Signal

In a case in which image data indicating a subject are recorded in theremovable memory or the like, and printing or another operation isconsidered, the number of pixels of the area image sensor 15 must begreater than a predetermined number in order to obtain high-qualityimage data. Therefore, the effective number of pixels of the area imagesensor 15 in the present embodiment is 5400 pixels in the horizontaldirection and 3600 pixels in the vertical direction, as shown in FIG. 2.The area image sensor 15 is provided with a large number of pixels inexcess of the effective pixels in the horizontal direction and thevertical direction, but in order to simplify the present specification,no description is given of the processing that relates to pixels otherthan the effective pixels.

On the other hand, the liquid crystal panel 42 is provided with 1024pixels in the horizontal direction and 768 pixels in the verticaldirection, as described above, and is configured so that the image ofthe subject is displayed in the subject image display region (R1 shownin FIG. 2). In the present embodiment, in order to display the image ofthe subject as large as possible while maintaining the aspect ratio(2:3) of the area image sensor 15, a rectangular region having an aspectratio of 2:3 in which the top edge and left and right edges are adjacentto the top edge and left and right edges of the liquid crystal panel 42is used as the subject image display region R1 for displaying the imageof the subject. The remaining region is the information display region(region shown in FIG. 2) for displaying characters indicatingimage-capturing conditions or other information. Consequently, thesubject image display region R1 in the liquid crystal panel 42 iscomposed of 1024 pixels in the horizontal direction and 682 pixels inthe vertical direction. As described above, the number of pixels of thearea image sensor 15 and the number of pixels of the liquid crystalpanel 42 are not the same in the present embodiment.

Furthermore, since the display in the display section 40 is utilized bythe user to confirm the subject, when the delay between the timing atwhich the subject is captured by the area image sensor 15 and the timingat which the image of the captured subject is displayed by the displaysection 40 increases sufficiently to be noticeable by the user, thesubject seen in the EVF and the recorded image of the subject aremisaligned, and the EVF becomes extremely difficult to use. The delaymust therefore be minimal when the display section 40 is used as an EVF.

Therefore, in order for the image captured by the area image sensor 15to be displayed in the display section 40 so that the delay is soextremely short as to not be seen by the human eye, a configuration isadopted in the present embodiment whereby various types of processingare performed by the area image sensor 15 and the image data generationsection 20, and the display section 40 causes the image data generatedas a result of the processing to be displayed at high speed.

In other words, the area image sensor 15 according to the presentembodiment is provided with a circuit capable of executing interlacedscanning for reading the detection results of the photodiodes at a ratioof 1 for every n (where n is an odd number) lines aligned in thevertical direction. An adder is also provided for adding m (where m is anatural number) detection results aligned in the horizontal directionamong the photodiodes for performing photoelectric conversion via colorfilters of the same color, and outputting l/m of the sum (i.e.,outputting the arithmetic average of the m detection results). Thepresent embodiment is configured so that when the display section 40 iscaused to function as an EVF, interlaced scanning and processing by theadder are executed in the area image sensor 15, whereby pixels in thehorizontal direction and the vertical direction are decimated, and theoutput data of a smaller number of pixels than the number of pixelsprovided to the area image sensor 15 are outputted, and the subject canthereby be captured at high speed.

In other words, in a live view mode for causing the display section 40to function as an EVF, the area image sensor 15 reads for lines in thevertical direction at a ratio of 1 for every n lines in accordance withthe horizontal synchronization signal SHsync. Processing for outputtingthe result of arithmetically averaging the detection results of mphotodiodes by the adder is also performed in accordance with the dataclock signal SDotclock. FIG. 3 shows an example of the method foroutputting the output data of a smaller number of pixels than the numberof pixels provided to the area image sensor 15 in the presentembodiment. In FIG. 3, the rectangles labeled R indicate photodiodesthat correspond to color filters for transmitting light in a redspectrum, the rectangles labeled G indicate photodiodes that correspondto color filters for transmitting light in a green spectrum, and therectangles labeled B indicate photodiodes that correspond to colorfilters for transmitting light in a blue spectrum.

As shown in FIG. 3, in a case in which the color filters of the pixelsindicated by rectangles are in a Bayer array, since a color filter ofonly one color corresponds to each pixel, the color of each pixel mustbe interpolated by utilizing the surrounding pixels. Therefore, whenlines are decimated to acquire the output data, decimation must beperformed so that the color filters of adjacent lines after decimationare of a different color. Therefore, in the present embodiment, byacquiring the detection values in the photodiodes of each line at aratio of 1 line for every n lines (where n is an odd number) as theoutput data, it is possible to acquire output data in which the color ofeach pixel can be specified by interpolation. In the present embodiment,a configuration is adopted in which the output data are acquired at aratio of 1 line for every 5 lines in order to make the number of linesin the vertical direction of the area image sensor 15 as close aspossible to the number of lines in the vertical direction of the subjectimage display region R1 of the liquid crystal panel 42. In FIG. 3, theleft-directed arrows indicate that output data are acquired at a ratioof 1 line for every 5 lines, and in this example, the number of lines inthe vertical direction is ⅕, i.e., 720.

In a case in which the color filters are in a Bayer array, the colors ofadjacent pixels in the horizontal direction are different, and the samecolor of color filter occurs at every other position. Therefore,decimation processing can essentially be performed by adding m at everyother pixel for pixels aligned in the horizontal direction andmultiplying the sum by l/m (i.e., calculating the arithmetic average ofm detection results). In the present embodiment, m is set to 3, due tosuch factors as limitations for the sake of image quality in cases inwhich adding is performed by the adder. In the configuration shown inFIG. 3, in the lowest line shown, the detection results of the threephotodiodes aligned in the horizontal direction that are photodiodes forperforming photoelectric conversion via green color filters are added byan adder S1 and multiplied by ⅓, and the detection results of the threephotodiodes aligned in the horizontal direction that are photodiodes forperforming photoelectric conversion via red color filters are added byan adder S2 and multiplied by ⅓. In this example, the number of pixelsin the horizontal direction is ⅓, i.e., 1800 pixels. In FIG. 2, the datasize after decimation in the area image sensor 15 is indicated by thedashed-line rectangle 15 a.

As described above, in the area image sensor 15, the number of lines inthe vertical direction may be set to 720, and the number of pixels inthe horizontal direction may be set to 1800. However, in suchdecimation, since n is an odd number in the vertical direction, m is anatural number in the horizontal direction, and there are other suchlimitations for the sake of image quality, the number of pixels afterdecimation and the number of pixels of the subject image display regionR1 of the liquid crystal panel 42 do not readily coincide. In a case inwhich n and m differ, as described above, the aspect ratio differsbetween the subject and the subject image on the liquid crystal panel42.

A configuration is therefore adopted in the present embodiment in whichresizing is further performed in the image data generation section 20for the decimated output data, and image data are generated for displayin the subject image display region R1 of the liquid crystal panel 42.In other words, the image data generation section 20 is provided with apixel interpolation section 20 a, a color reproduction processingsection 20 b, a filter processing section 20 c, a gamma correctionsection 20 d, and a resizing processing section 20 e. In thisconfiguration, the number of pixels in the vertical direction and thehorizontal direction is modified by the resizing processing section 20 ein the process of generating the image data, and image data aregenerated which are equivalent to the number of pixels of the subjectimage display region R1 of the liquid crystal panel 42.

The line buffer 52 a is a buffer memory for temporarily recording thedecimated output data outputted from the area image sensor 15, and whenthe decimated output data are outputted from the area image sensor 15,the output data are temporarily recorded in the line buffer 52 a by theprocessing of the image data generation section 20. The pixelinterpolation section 20 a imports data of the necessary number ofpixels for generating the colors of the two channels missing in eachpixel in the Bayer array from the line buffer 52 a, and while doing so,generates the colors of the two channels by interpolation processing. Asa result, three channels of data are generated in each pixel. The colorreproduction processing section 20 b then performs color conversionprocessing for color matching by performing a 3×3 matrix computationbased on the generated data. The data generated by color conversionprocessing are temporarily recorded in the line buffer 52 b. The filterprocessing section 20 c then executes sharpness adjustment, noiseremoval processing, and other processing by filter processing. The gammacorrection section 20 d then executes gamma correction to compensate fora characteristic difference between the colors indicated by thegradation values of the output data of the area image sensor 15 and thecolors indicated by the gradation values of the image data handled bythe display section 40. The data generated by gamma correction aretemporarily recorded in the line buffer 52 c.

The data recorded for each line, i.e., line by line, in the line buffer52 c are the number of pixels decimated in the area image sensor 15. Inother words, data of 720 lines in the vertical direction and 1800 pixelsin the horizontal direction are recorded line by line. The resizingprocessing section 20 e performs resizing by sequentially referencingthe data recorded in the line buffer 52 c to perform interpolationcomputation processing and specify the gradation value of each channelin the positions between pixels. In the present embodiment, since thedecimation in the area image sensor 15 described above is ⅕ in thevertical direction and ⅓ in the horizontal direction, the aspect ratioof the decimated data differs from the aspect ratio of the output dataof the area image sensor 15, as shown in the rectangle 15 a in FIG. 2.Therefore, the resizing processing section 20 e first performs reductionprocessing for reduction to a size of approximately 57% in thehorizontal direction based on the data recorded in the line buffer 52 c.As a result, the number of pixels in the horizontal direction is set to1024. The resizing processing section 20 e also performs reductionprocessing for reduction to a size of approximately 95% in the verticaldirection. As a result, image data are generated for which there are1024 pixels in the horizontal direction and 682 lines in the verticaldirection. The generated image data are recorded line by line in theline buffer 52 d.

In the present embodiment, by the processing described above, generationprocessing is performed for generating image data that can be displayedin the subject image display region R1 of the liquid crystal panel 42based on the output data of the area image sensor 15, but the outputdata of the area image sensor 15 have 720 lines in the verticaldirection, whereas the number of lines of the image data in the verticaldirection is 682, and the number of lines of the liquid crystal panel 42in the vertical direction is 768. In other words, different numbers oflines are required to capture a single frame and to display a singleframe.

Therefore, in the present embodiment, the horizontal synchronizationsignal SHsync, the vertical synchronization signal SVsync, the dataactive signal SDactive, and the data clock signal SDotclock of the areaimage sensor 15 are set to the cycle necessary for driving the areaimage sensor 15. In other words, the timing generator 30 outputs thehorizontal synchronization signal SHsync the number of times and at thetiming whereby the decimation in the vertical direction such asdescribed above can be performed in the area image sensor 15, and theoutput data of the number of lines of a single frame can be acquiredwithin the period prescribed by the vertical synchronization signalSVsync. The timing generator 30 also outputs the data clock signalSDotclock the number of times and at the timing whereby decimation inthe horizontal direction such as described above can be performed, andthe output data of the number of pixels of a single line can be acquiredwithin the period prescribed by the horizontal synchronization signalSHsync.

On the other hand, in order to minimize the delay period and performdisplay in the liquid crystal panel 42 based on the output dataoutputted line by line from the area image sensor 15, a configuration isadopted in the present embodiment whereby the horizontal synchronizationsignal DHsync is outputted at the time that the image data for displayof each line of the liquid crystal panel 42 are prepared. In otherwords, the liquid crystal panel 42 in the present embodiment is capableof displaying lines for which processing by the resizing processingsection 20 e is ended. The timing generator 30 therefore outputs thehorizontal synchronization signal DHsync for displaying the N^(th) linein the vertical direction of the liquid crystal panel 42 at the timethat the processing for generating the image data of the N^(th) line(where N is a natural number) is ended.

Specifically, the timing generator 30 is provided with a progressinformation acquisition section 30 a, and the progress informationacquisition section 30 a is capable of acquiring, from the resizingprocessing section 20 e, progress information for indicating a line forwhich the processing for generating image data is ended in the resizingprocessing section 20 e. Consequently, through this progressinformation, it is possible to specify a line that can be displayed inthe liquid crystal panel 42 based on the image data. Therefore, in thisconfiguration, the timing generator 30 outputs the horizontalsynchronization signal DHsync in synchrony with the timing at which theprocessing for generating the image data of each line is ended, anddisplay of a line for which the processing for generating the image datais thereby started in the liquid crystal panel 42. Through thisconfiguration, display of each line does not start before preparation ofthe image data is finished, and each line can be immediately displayedwith the display preparation thereof is finished.

Since the liquid crystal panel 42 is preferably capable of displayingthe pixels of each line of the liquid crystal panel 42 within thehorizontal synchronization period prescribed by the output timing of thehorizontal synchronization signal DHsync, the timing generator 30outputs the data active signal DDactive and the data clock signalDDotclock so that the pixels of a single line can be displayed within aperiod assumed to be the period in which the horizontal synchronizationperiod prescribed by the output timing of the horizontal synchronizationsignal DHsync is shortest.

In the present embodiment, the vertical synchronization signal SVsync ofthe area image sensor 15 and the vertical synchronization signal DVsyncof the liquid crystal panel 42 are set so as to be synchronized in orderto prevent the output data from the area image sensor 15 and the displayby the liquid crystal panel 42 from becoming inconsistent by frameunits. In other words, the timing generator 30 outputs the verticalsynchronization signal DVsync of the display section 40 after apredetermined period from the timing at which the verticalsynchronization signal SVsync of the area image sensor 15 is outputted.As a result, the cycles of the vertical synchronization signals SVsync,DVsync are the same and constant in the present embodiment.Consequently, the display in the liquid crystal panel 42 of the subjectcaptured by the area image sensor 15 is not delayed by the period of asingle frame or longer, and a display of an image of the subjectcaptured at the same timing does not remain on the liquid crystal panel42 for a period of a plurality of frames.

Since the horizontal synchronization period prescribed by the horizontalsynchronization signal DHsync of the liquid crystal panel 42 is ofvariable length in the present embodiment, the cycles of the verticalsynchronization signals SVsync, DVsync are the same and constant evenwhen the horizontal synchronization period varies. Specifically, thetiming generator 30 controls the output signal so that the verticalsynchronization period for displaying a single frame is constant bylengthening or shortening the horizontal synchronization period withrespect to a reference period TH determined in advance, and therebycanceling out the time fluctuation from a reference period TH. Thereference period TH is configured as the horizontal synchronizationperiod in a case in which each of the total number of lines of theliquid crystal panel 42 is displayed for an equal period within thevertical synchronization period.

In the subject image display region R1, a state is attained in which thehorizontal synchronization period can be lengthened by waiting to outputthe horizontal synchronization signal DHsync until the processing forgenerating the image data of each line is ended. In the informationdisplay region R2 of the liquid crystal panel 42 for displayingcharacters indicating image-capturing conditions or other information,the horizontal synchronization period is made shorter than the referenceperiod TH so as to cancel out the cumulative total of the difference ofthe horizontal synchronization period lengthened in the subject imagedisplay region R1 and the reference period TH.

FIG. 4 shows the horizontal synchronization signal DHsync outputted fromthe timing generator 30 configured as described above, and also showsthe data active signal DDactive, the data clock signal DDotclock, andthe progress information. The progress information outputted from theresizing processing section 20 e in the present embodiment is composedof a single pulse in which a low-level output is maintained as theprocessing for generating the image data for a single line is beingexecuted, and a high-level output occurs at a predetermined period atthe time that the processing for generating the image data for a singleline is ended.

When the timing generator 30 acquires the progress information throughthe progress information acquisition section 30 a, the horizontalsynchronization signal DHsync is outputted in synchrony with the pulseof the progress information by the processing of the display controlsection 30 b. Therefore, even in a case in which the processing forgenerating the image data of a certain line fails to occur within thereference period TH, the horizontal synchronization signal DHsync is notoutputted until the generation processing is ended, and a horizontalsynchronization period TDH becomes longer than the reference period TH.Consequently, in a case in which the processing for generating the imagedata of a certain line fails to occur within the reference period TH,display of the certain line is not started in the liquid crystal panel42 until the generation processing is completed. Display is also notperformed before preparation of the image data of each line is ended.Furthermore, since the horizontal synchronization signal DHsync isoutputted when the processing for generating the image data of a certainline is ended, the image data of each line is displayed without delaywhen preparation thereof is ended. As described above, since the liquidcrystal panel 42 in the present embodiment is driven in a state in whichthe horizontal synchronization period TDH may be longer than thereference period TH, the present invention is suitable for applicationto a situation in which the period for generating the image data of asingle line to be displayed by the liquid crystal panel 42 mayfluctuate. A possible example of such a situation is one in which thespeed of data output processing of the area image sensor 15 or theprocessing for generating image data by the image data generationsection 20 may differ for each line. The present invention may also, ofcourse, be applied in a situation in which the processing speed differsfor each line depending on the image-capturing conditions or thehardware used for capturing and image. For example, the presentinvention can be applied to a configuration in which the verticalsynchronization period or the horizontal synchronization period of thearea image sensor 15 fluctuates, or the period needed for processing forgenerating image data fluctuates due to an operation of the operatingsection 55 by the user. The present invention can also be applied to aconfiguration in which the vertical synchronization period or thehorizontal synchronization period of the area image sensor 15fluctuates, or the period needed for processing for generating imagedata fluctuates due to the changing of an interchangeable EVF or aninterchangeable lens.

As described above, in the subject image display region R1 in thepresent embodiment, the timing generator 30 adjusts the horizontalsynchronization period TDH in accordance with the progress informationoutputted from the resizing processing section 20 e. The horizontalsynchronization signal DHsync may therefore be lengthened according tothe progress of the processing for generating the image data to bedisplayed in the subject image display region R1, and the horizontalsynchronization period TDH prescribed by the horizontal synchronizationsignal DHsync of the liquid crystal panel 42 is not necessarilyconstant. On the other hand, since the vertical synchronization periodprescribed by the vertical synchronization signal DVsync is constant inthe present embodiment, as described above, the timing generator 30 setsthe output timing of the horizontal synchronization signal DHsync sothat a horizontal synchronization period TDH2 is shorter than theabovementioned reference period TH in the information display region R2,so that displaying of all the lines of the liquid crystal panel 42 endswithin the vertical synchronization period even in a case in which thehorizontal synchronization period TDH in the subject image displayregion R1 is lengthened.

In other words, since the data (referred to as OSD data) of thecharacters indicating the image-capturing conditions or otherinformation can be created in advance and recorded in advance in theVRAM 51 irrespective of operation of the area image sensor 15, anappropriate display can be performed without overtaking the reading ofdata even when a display based on the OSD data is executed according toa short horizontal synchronization period. Therefore, in the presentembodiment, the horizontal synchronization period in the informationdisplay region R2 for displaying characters indicating image-capturingconditions or other information is set so as to be shorter than that ofthe subject image display region R1 for producing a display based on theoutput data of the area image sensor 15.

Specifically, the timing generator 30 adjusts the output timing of thehorizontal synchronization signal DHsync, and thereby shortens thehorizontal synchronization period TDH2 so that the sum of thedifferences of the lengthened horizontal synchronization period TDH andthe reference period TH in the subject image display region R1, and thesum of the differences of the shortened horizontal synchronizationperiod TDH2 and the reference period TH in the information displayregion R2 coincide. As a result, the following relation obtains:horizontal synchronization period TDH2<reference period≤horizontalsynchronization period TDH. Various configurations can be adopted in theinformation display region R2 as configurations whereby the horizontalsynchronization signal DHsync is outputted so that the horizontalsynchronization period TDH2 is shorter than the reference period TH. Forexample, as shown in FIG. 4, a configuration may be adopted in which theperiod of shortening in each line is the value ΔT2 obtained by dividingthe sum (ZΔT1) of the delay ΔT1 with respect to the horizontalsynchronization period TDH by the number of lines L2 of the informationdisplay region R2, the delay ΔT1 being generated in the subject imagedisplay region R1. In other words, a configuration may be adopted inwhich the value of horizontal synchronization period TDH-ΔT2 is assumedto be the horizontal synchronization period TDH2 in the informationdisplay region R2.

As described above, in order to produce a suitable display in eachregion based on the horizontal synchronization signal adjusted for eachregion of the liquid crystal panel 42 in the present embodiment, theline numbers of the portions of the liquid crystal panel 42 thatcorrespond to the subject image display region R1 and the informationdisplay region R2 are determined in advance. For example, in the exampleshown in FIG. 2, lines 1 through 682 are the subject image displayregion R1, and lines 683 through 768 are the information display regionR2. Therefore, the timing generator 30 outputs the horizontalsynchronization signal DHsync so that the horizontal synchronizationperiod TDH2 is shorter than the abovementioned reference period THduring display in the information display region R2 that corresponds tolines 683 through 768, while the timing generator 30 outputs thehorizontal synchronization signal DHsync at a timing in accordance withthe abovementioned progress information during display in the subjectimage display region R1 that corresponds to lines 1 through 682.

The ASIC 200 is also provided with an image data output section 201, andthe image data output section 201 outputs the image data (Data) recordedin the line buffer 52 d to the display section 40 line by line duringdisplay of lines 1 through 682 of the liquid crystal panel 42. As aresult, the image of the subject captured by the area image sensor 15 isdisplayed in the subject image display region R1. The CPU 50 records OSDdata to the VRAM 51 prior to at least display in an information displayregion R2. During display in lines 683 through 768 of the liquid crystalpanel 42, the image data output section 201 outputs the OSD datarecorded in the VRAM 51 to the display section 40 line by line as theimage data (Data). As a result, characters indicating image-capturingconditions and the like are displayed in the information display regionR2.

Through this configuration, display of image-capturing conditions orother information by the OSD data is performed within a short horizontalsynchronization period in the information display region R2, while thesubject captured by the area image sensor 15 is displayed in the subjectimage display region R1 in a state of minimal delay. Since thehorizontal synchronization period is also controlled as described aboveso that the sum of the differences of the lengthened horizontalsynchronization period TDH and the reference period TH in the subjectimage display region R1, and the sum of the differences of the shortenedhorizontal synchronization period TDH2 and the reference period TH inthe information display region R2 coincide, display by the displaysection 40 can be performed in a state in which the cycles of thevertical synchronization signals SVsync, DVsync are the same andconstant. Consequently, the display in the liquid crystal panel 42 ofthe subject captured by the area image sensor 15 is not delayed by theperiod of a single frame or longer, and the same image does not remaindisplayed on the liquid crystal panel 42 for a plurality of frameperiods.

(3) Other Embodiments

The embodiment described above is an example of an implementation of thepresent invention, and the present invention is not limited to aconfiguration in which determination is made based on progressinformation for each line as to whether processing for generating imagedata is ended, and a line for which the generation processing is endedis displayed. A configuration may be adopted in which a determination ismade based on progress information as to whether processing forgenerating image data is ended for individual predetermined data units,the predetermined data units being i lines, j pixels (where i and j arenatural numbers), or other units, and a predetermined data unit forwhich the generation processing is ended is displayed. The embodimentsdescribed hereinafter may also be combined with the embodiment describedabove, and various other embodiments are also possible.

For example, a back porch of the horizontal synchronization signalDHsync may be lengthened when the horizontal synchronization period TDHis made longer than the reference period TH. In this configuration, theoutput period of progress information from the resizing processingsection 20 e is detected in the progress information acquisition section30 a in the configuration shown in FIG. 1. In other words, the periodTS(N−1) is detected between the progress information outputted at thetime that processing for generating the image data of the (N−1)^(th)line is ended and the progress information outputted at the time thatprocessing for generating the image data of the N^(th) line is ended.The timing generator 30 then determines the length of the back porch ofthe horizontal synchronization signal DHsync of the N^(th) line based onthe period TS(N−1), and outputs various types of signals.

In other words, by the processing of the display control section 30 b,the timing generator 30 outputs a signal DHsync2 indicating a prechargeperiod when a period ΔT1 has elapsed after outputting of the horizontalsynchronization signal DHsync of the N^(th) line, as shown in FIG. 5,the period ΔT1 being obtained by subtracting the length of the referenceperiod TH from the length of the period TS(N−1). By the processing ofthe display control section 30 b, the timing generator 30 then outputsDDactive when the predetermined precharge period has elapsed afteroutputting of the signal DHsync2, and outputs the horizontalsynchronization signal DHsync of the (N+1)^(th) line, providing a frontporch having a predetermined period after maintaining the level ofDDactive until the data clock signal DDotclock of the number of pixelsof a single line is outputted. The period from the start of theprecharge period until the end of the front porch coincides with thereference period TH. Consequently, the horizontal synchronization periodTDH, which is the period between the horizontal synchronization signalDHsync of the N^(th) line and the horizontal synchronization signalDHsync of the (N+1)^(th) line, is the sum of the reference period TH andΔT1. As a result, N lines can be displayed with precharging, inversion,and other operations synchronized with the signal DHsync2 in the liquidcrystal panel 42, and the horizontal synchronization period TDH can bemade longer than the reference period TH.

In the first embodiment described above, since the front porch of thehorizontal synchronization signal DHsync is lengthened, the back porchperiod can be set as a constant period, and the period for performingprecharging, inversion, and other operations can be provided accordingto normal specifications.

In the embodiment described above, the horizontal synchronization signalSHsync is outputted so that the horizontal synchronization period isshorter in the information display region R2 of the liquid crystal panel42 than in the subject image display region R1, in order to cause thecycle of the vertical synchronization signal SVsync of the area imagesensor 15 and the cycle of the vertical synchronization signal DVsync ofthe liquid crystal panel 42 to coincide, but the cycle of the verticalsynchronization signal SVsync and the cycle of the verticalsynchronization signal DVsync of the liquid crystal panel 42 can be madeto coincide by another method. For example, since the area image sensor15 has a larger number of lines than the liquid crystal panel 42 in anormal image-capturing device, in a case in which the horizontalsynchronization period that should be maintained within a specificvertical synchronization period is assumed to be equal, the horizontalsynchronization signal DHsync of the liquid crystal panel 42 is shorterthan the horizontal synchronization signal SHsync of the area imagesensor 15. Consequently, even in a case in which the horizontalsynchronization signal DHsync of the liquid crystal panel 42 islengthened, it is not often necessary to lengthen the verticalsynchronization period of the liquid crystal panel 42 according to thelengthening of the horizontal synchronization signal DHsync. In a casein which lengthening the horizontal synchronization signal DHsync causesthe vertical synchronization signal DVsync of the liquid crystal panel42 to be longer than the vertical synchronization signal SVsync of thearea image sensor 15, the vertical synchronization signal SVsync of thearea image sensor 15 may be lengthened, and the vertical synchronizationsignal DVsync and vertical synchronization signal SVsync may besynchronized.

In the embodiment described above, a configuration is adopted in whichprogress information is acquired which indicates for each line whetherthe resizing processing of the processing for generating image data isended, but any configuration may be adopted insofar as progressinformation for the processing of the final step is acquired, even in acase in which the final step of the processing for generating the imagedata is not the resizing processing. A configuration may also be adoptedin which the progress information is acquired for processing of a stepprior to the final step (e.g., a step in which the processing time mayfluctuate), insofar as processing can be performed at such a high speedthat the processing time of the final step of processing for generatingthe image data can be ignored, processing can be performed in a certaintime, or it is possible to predict the ending of the final step. In acase in which an image processing step is included for referencing thedata of a plurality of lines and generating data of a single line in theprocessing for generating the image data, the progress information maybe acquired for the included step. The timing at which the processingfor generating image data is ended may thus be computed based on theprogress information, or specified as the timing at which the progressinformation is acquired.

FIG. 6 is a view showing an image-capturing device 1 that is configuredso as to acquire progress information for a plurality of imageprocessing steps for referencing the data of a plurality of lines togenerate data of a single line. In FIG. 6, the same reference symbols asthose of FIG. 1 are used to refer to constituent elements that are thesame as those in FIG. 1. A timing generator 300 of the image-capturingdevice 1 shown in FIG. 6 is capable of acquiring progress informationwhich indicates a line for which outputting of the output data from thearea image sensor 15 is completed, and a line for which the processingfor generating data in each of the color reproduction processing section20 b, the gamma correction section 20 d, and the resizing processingsection 20 e of the image data generation section 20 is ended. By theprocessing of a display control section 300 b, the timing generator 300is capable of outputting a trigger signal (e.g., a horizontalsynchronization signal) for starting processing for generating data of asingle line to each of the pixel interpolation section 20 a, the filterprocessing section 20 c, and the resizing processing section 20 e.

In other words, in this embodiment, the image processing steps includean X^(th) image processing step and an (X+1)^(th) image processing step,where X is a natural number equal to or less than (a total number of theimage processing steps−1), with the X^(th) image processing step and the(X+1)^(th) image processing step being in a relationship such thatprocessing for generating a Z^(th) one of the predetermined data units,where Z is a natural number, by the (X+1)^(th) image processing stepcannot be started unless a Y^(th) one of the predetermined data units,where Y is a natural number, is generated by the X^(th) image processingstep. Then, the display control section 300 b of the timing generator300 is configured to cause the image data generation section 20 to startthe processing for generating the Z^(th) one of the predetermined dataunits by the (X+1)^(th) image processing step when the progressinformation specifies that the Y^(th) one of the predetermined dataunits has been generated by the X^(th) image processing step.

More specifically, in the embodiment shown in FIG. 6, processing of dataof an L^(th) line can be executed in the pixel interpolation section 20a when the output data of a K^(th) line is outputted from the area imagesensor 15, and as a result of line-by-line processing by the pixelinterpolation section 20 a and the color reproduction processing section20 b, determination is made in advance that the processing of data of anM^(th) line in the filter processing section 20 c can be executed whenprocessing of the data of the L^(th) line is ended. As a result ofline-by-line processing by the filter processing section 20 c and thegamma correction section 20 d, determination is also made in advancethat the processing for generating image data of an N^(th) line can bestarted in the resizing processing section 20 e when processing of thedata of the M^(th) line is ended.

The timing generator 300 specifies that output data of the K^(th) lineis outputted from the area image sensor 15 based on a horizontalsynchronization signal SHsync having a prescribed cycle outputted by thetiming generator 300. In a case in which determination is made that theoutput data of the K^(th) line is outputted from the area image sensor15, the timing generator 300 outputs the trigger signal to the pixelinterpolation section 20 a to start data processing of the L^(th) line.In a case in which a progress information acquisition section 300 aspecifies that processing of the data of the L^(th) line is ended in thecolor reproduction processing section 20 b, the timing generator 300outputs the trigger signal to the filter processing section 20 c tostart data processing of the M^(th) line. In a case in which theprogress information acquisition section 300 a specifies that processingof the data of the M^(th) line is ended in the gamma correction section20 d, the timing generator 300 outputs the trigger signal to theresizing processing section 20 e to start processing for generating theimage data of the N^(th) line.

When determination is made that processing for generating the image dataof the N^(th) line by the resizing processing section 20 e is ended, thetiming generator 300 outputs the horizontal synchronization signalDHsync for displaying the N^(th) line, in the same manner as in theembodiment described above. In other words, in the image data generationsection 20, in an image processing step in which it is possible to startgenerating data of a line which is subsequent to recording of the dataof two or more lines in a line buffer, a determination is made as towhether processing for generating data of the lowest necessary number oflines is ended, and the next image processing step is started at thetime that the generation processing is ended. Through thisconfiguration, processing for each line does not start beforepreparation of the necessary data for executing each step is finished,and processing for each line can be immediately started when the data ofeach line are prepared. As a result, the wait time during execution ofeach image processing step is minimized. In the present embodiment,since the data of only the lowest necessary number of lines istemporarily recorded in the line buffers 52 a through 52 d, the capacityof the line buffers 52 a through 52 d can be minimized.

Furthermore, the display section 40 is an EVF which uses a liquidcrystal panel in the embodiment described above, but the display section40 may be a display section other than an EVF. For example, the displaysection 40 may be a display section which uses a liquid crystal panelattached to a back surface of the image-capturing device 1, or a displaysection other than a liquid crystal panel may be used. Theimage-capturing device 1 may also be a single-lens reflex cameraprovided with a mirror, the image-capturing device 1 may be a moviecamera, or the image-capturing device 1 may be a mobile telephone orother device provided with image-capturing functionality. The colorfilters are also in a Bayer array in the area image sensor 15 describedabove, but the present invention may also be applied in animage-capturing device which utilizes a sensor configured in anarrangement other than a Bayer array. The line buffer 52 d may be a linebuffer, but may also be a VRAM provided with a recording capacity forrecording the image data of a single frame. Through this configuration,various types of processing can be performed based on the image data tobe displayed. The horizontal synchronization period is also preferablylengthened with respect to a reference period, and various types ofperiods can be assumed as the reference period. For example, the cycleof the horizontal synchronization signal SHsync of the area image sensor15, the cycle for generating the image data, and other cycles may beused as the reference period. Furthermore, various forms may be adoptedas the form in which various types of signals are transmitted from thetiming generator 30 to the display section 40, and signals may betransmitted by HDMI (high-definition multimedia interface) and othermethods. The directions in the embodiment described above may also bereversed. In the horizontal direction, for example, display may beperformed from left to right or from right to left.

Furthermore, the OSD data are preferably image data indicatingpredetermined information to be displayed in the information displayregion of the display section, and a configuration may be adopted inwhich the predetermined information to be displayed includes varioustypes of information other than that of image-capturing conditions,e.g., information indicating the remaining amount of power in a batterymounted in the image-capturing device 1, or other information. Variousconfigurations other than the configuration described above may also beemployed as the configuration for making the cycles of the verticalsynchronization signals SVsync, DVsync the same and constant. Forexample, a configuration may be adopted in which, after display in thesubject image display region R1 is performed, the smallest period thatcan be set for displaying the OSD data in the information display regionR2 is used as the horizontal synchronization period in the informationdisplay region R2, whereby display of all the lines of the liquidcrystal panel 42 is completed before the output timing of the verticalsynchronization signal DVsync, and the vertical synchronization signalDVsync is outputted at a prescribed output timing after waiting for theremainder of the period.

GENERAL INTERPRETATION OF TERMS

In understanding the scope of the present invention, the term“comprising” and its derivatives, as used herein, are intended to beopen ended terms that specify the presence of the stated features,elements, components, groups, integers, and/or steps, but do not excludethe presence of other unstated features, elements, components, groups,integers and/or steps. The foregoing also applies to words havingsimilar meanings such as the terms, “including”, “having” and theirderivatives. Also, the terms “part,” “section,” “portion,” “member” or“element” when used in the singular can have the dual meaning of asingle part or a plurality of parts. Finally, terms of degree such as“substantially”, “about” and “approximately” as used herein mean areasonable amount of deviation of the modified term such that the endresult is not significantly changed. For example, these terms can beconstrued as including a deviation of at least ±5% of the modified termif this deviation would not negate the meaning of the word it modifies.

While only selected embodiments have been chosen to illustrate thepresent invention, it will be apparent to those skilled in the art fromthis disclosure that various changes and modifications can be madeherein without departing from the scope of the invention as defined inthe appended claims. Furthermore, the foregoing descriptions of theembodiments according to the present invention are provided forillustration only, and not for the purpose of limiting the invention asdefined by the appended claims and their equivalents.

What is claimed is:
 1. An image-displaying device comprising: an imagedata generation section including a circuit configured to generate apredetermined unit of image data based on output data captured by animage-capturing section, the output data corresponding to a part of animage of a subject; and a display section configured to display eachline of an image of a subject for display based on the predeterminedunit of image data for a horizontal synchronization period prescribed bya horizontal synchronization signal, the horizontal synchronizationperiod being variable, wherein a vertical synchronization period todisplay a single frame is constant by lengthening or shortening thehorizontal synchronization period with respect to a reference perioddetermined in advance.
 2. The image-displaying device according to claim1, further comprising: a timing generator configured to output timinginformation indicative of timing, wherein the display section is furtherconfigured to display the image of the subject after the display sectionhad received the timing information.
 3. An image data generation deviceto be used with an image-capturing device and a display devicecomprising: an image data generation section including a circuitconfigured to generate a predetermined unit of image data based onoutput data captured by the image-capturing device, the output datacorresponding to a part of an image of a subject; and a timing generatorconfigured to output timing information to the display device, thetiming information indicating a horizontal synchronization periodprescribed by a horizontal synchronization signal to display each lineof an image of a subject for display based on the predetermined unit ofimage data on the display, wherein the horizontal synchronization periodis variable, and a vertical synchronization period to display a singleframe is constant by lengthening or shortening the horizontalsynchronization period with respect to a reference period determined inadvance.
 4. The image-displaying device according to claim 1, whereinthe horizontal synchronization period is variable in processing fromimage capturing by the image-capturing section to display by the displaysection.
 5. The image data generation device according to claim 3,wherein the horizontal synchronization period is variable in processingfrom image capturing by the image-capturing device to display by thedisplay device.
 6. An image-displaying device comprising: an image datageneration section including a circuit configured to generate apredetermined unit of image data based on output data captured by animage-capturing section, the output data corresponding to a part of animage of a subject; and a display section configured to display eachline of an image of a subject for display based on the predeterminedunit of image data for a horizontal synchronization period prescribed bya horizontal synchronization signal, the horizontal synchronizationperiod being variable, wherein the display section is further configuredto display each line of an image of a subject simultaneously with endinggeneration of image data of the line by the image data generationsection, and a vertical synchronization period to display a single frameis constant by lengthening or shortening the horizontal synchronizationperiod with respect to a reference period determined in advance.